From 5576588c2d4d6bc09fde0b32d0e072884ee46e0d Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Tue, 5 Dec 2023 22:02:41 -0500
Subject: [PATCH] Fix drive enables, go back to FF for non-existent ports.

---
 Machines/PCCompatible/PCCompatible.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Machines/PCCompatible/PCCompatible.cpp b/Machines/PCCompatible/PCCompatible.cpp
index 5b046cf8b..007ef0693 100644
--- a/Machines/PCCompatible/PCCompatible.cpp
+++ b/Machines/PCCompatible/PCCompatible.cpp
@@ -63,7 +63,7 @@ class FloppyController {
 		FloppyController(PIC &pic, DMA &dma, int drive_count) : pic_(pic), dma_(dma) {
 			// Default: one floppy drive only.
 			for(int c = 0; c < 4; c++) {
-				drives_[0].exists = drive_count >= c;
+				drives_[c].exists = drive_count > c;
 			}
 		}
 
@@ -795,7 +795,7 @@ class IO {
 					// Ignore serial port accesses.
 				break;
 			}
-			return 0;
+			return 0xff;
 		}
 
 	private: